sigsegv@rambler.ru wrote:
[ ... ]
> I don't know much about the history of Mac OS X, but I've read it was 
> based on open source BSD, tell me if I am wrong, but didn't they take a 
> free BSD, polished it, added pretty GUIs and packaged it as Mac OS X? 
> Mac OS X could be made up of 90% of open  sorce software! :-)

MacOS X is based on open source BSD, yes, although the direct ancestor is 
NEXTSTEP from NeXT, which was based on the Mach kernel from Avie Tenavian at 
CMU and a userland from BSD 4.3reno with some spices added from SunOS 3 and 4, 
as the NeXT hardware presented an ABI which closely resembled the 
Motorola-based Sun-3/35 hardware circa 1988.  The original NeXTs could run 
staticly-linked SunOS binaries, and NeXT bootstrapped the NEXTSTEP OS from 
SunOS during initial development.

After Apple purchased NeXT, the company released a transitional OS known as 
Rhapsody, which became MacOS X, during which time they updated the userland 
from the classic BSD-4.3 to an unencumbered BSD-4.4lite.  Somewhere around 
two-thirds of the changes made to get to MacOS X 10.0 were from NetBSD, the 
rest mostly from FreeBSD except for crypto which was from OpenBSD.  Since 
then, MacOS has been following the changes made to FreeBSD more closely than 
anything else, and I believe Apple's site gives credit to FreeBSD 5.x in 
particular.

The pretty GUI comes from updating NEXTSTEP's Display PostScript based window 
system with Quartz and Aqua, which uses PDF instead of DPS, but also supports 
the classic MacOS image model (QuickDraw, QuickTime) and OpenGL; this work was 
done under a team led by Mike Paquette.

The part of MacOS X which is open source is called Darwin, and there is a 
project page at http://www.opendarwin.org/ which provides a site which is 
probably much more familiar to BSD users than what you might find on 
www.apple.com.

-- 
-Chuck

PS: With regard to the thread, Flash usually sucks.  There are cool things 
done in flash, but 95% of it is used to advertise, and probably only 1 time in 
a hundred do you find a site which uses flash, yet also provides good access 
and coverage of the "real content" using normal links rather than flash or 
javascript-based navigation.